This invention relates to the problem of ingestion of fish and other marine and aquatic life by suction, random entry, or other means into intakes. An example of such a situation exists in the electric power generating field today. Whether oil-fired, coal-fired, or atomic, in their present configuration, power plants use water from nearby water sources for cooling purposes. This causes several unfavorable effects, one of which is the ingestion of fish and other marine and aquatic life into the cooling system water intakes by suction, random entry, or other means. The same problem can exist in any situation where water or materials in the water are required for some purpose and are obtained from water bodies containing marine life.